Grow Your Blog Audience: Enable 3rd Party Commenting System
I found that my G+ friends could not drop their comments via G+ on my blog when I enabled Disqus a few weeks back so I contacted the Support at Disqus regarding that and their response was:
To clarify, although users can connect their Google account with their Disqus account, they cannot comment with their Google Plus account at this time. Let us know if you have any other questions.
Brittany - Product Support Disqus
As a blogger for the past three months, I am keen on updating my blog to be appealing to my readers as well as Search Engines. In order to take blogging into the next level, one should do Search Engine Optimisation to his or her blog. Now many bloggers have great contents on their blog and some even get thousands of visitors a month. It is a sad case if you don't make an effort to learn about blogging further when some people out there are mastering blogging tricks and bringing their blogs on the first page of Google thus being a blogger by profession.
I have always wanted to have my Facebook friends and Twitter followers commenting on my blog. Most of the time, when I have not published any new post, I would still be getting a decent amount of audience on my blog on my popular articles. I know they are not from G+, so they are not able to comment on my blog or like the post. So I enabled Disqus thread on my blogger account. With this, I hope more readers would be engaged on my thoughts via my posts.
For Disqus to work you should disable G + comment system. All you should do is to create an account an install the widget via their easy-install method on http://disqus.com/
I hope this work for you and do let me know if you like the changes on my blog.